The present invention relates to a refrigerating apparatus having a refrigerating cycle and in particular to a flow amount control valve for controlling the amount of flow of a refrigerant.
In addition, the present invention relates to a refrigerating apparatus having a flow amount control valve for adjusting the amount of flow of a refrigerant that is circulated in a refrigerating cycle.
As a related art reference, a refrigerating flow amount control valve (disclosed in Japanese Patent Examined Publication No. 578739) is known. In the related art reference, the rotating motion of a stepping motor is converted into upward and downward motions of a tapered spindle (valve) through a gear. The amount of flow of the refrigerant is varied based on the amount of the space between an end of the spindle and a valve seat located in the refrigerant flow path.
The spindle moves upwardly and downwardly corresponding to the rotating angle of the stepping motor and varies the amount of the gap with the valve seat, thereby freely control the amount of the refrigerant.
In the conventional refrigerant flow amount control valve, the amount of flow of the refrigerant is adjusted corresponding to the amount of gap between the end of the spindle and the valve seat. Thus, the maximum amount of flow of the refrigerant depends on the refrigerant flow path formed at the valve seat.
The refrigerant flow amount control valve that has the above-described construction is used as an expansion means (such as an electric expanding valve or a capillary tube that throttles the flow amount of the refrigerant) in the refrigerating cycle. Thus, even if the refrigerant flow amount control valve has a pressure loss there is no problem. Instead, the refrigerant flow amount control valve is used to adjust the pressure loss.
However, when a refrigerant cycle that restricts the flow direction of the refrigerant in a heat exchanger is designed, if the refrigerating cycle is reversely operated, the position of the expansion means should be changed depending on the input side or the output side of the heat exchanger.
In other words, when the refrigerant flow amount control valve on the input side of the heat exchanger is used as an expansion means, if the refrigerant flow amount control valve on the output side of the heat exchanger has a pressure loss, the operation efficiency of the refrigerating cycle deteriorates. Likewise, when the refrigerant flow amount control valve on the output side of the heat exchanger is used as an expansion means, if the refrigerant flow amount control valve on the input side of the heat exchanger has a pressure loss, the operation efficiency of the refrigerating cycle deteriorates.
Thus, in the conventional construction, a pipe with a larger diameter is disposed in parallel with the refrigerant flow amount control valve so as to prevent a pressure loss from taking place and to bypass the refrigerant flow amount control valve that is not used as an expansion means.
Consequently, the conventional refrigerant flow amount control valve always requires a bypass valve that controls the flow in the bypass pipe. Thus, since the number of valves increases and the size of the refrigerating apparatus therewith increases, the requirement for a size reduction of the apparatus cannot be satisfied.
In addition to the refrigerant flow amount control valve, since a drive circuit and a control device for the bias valve are required, the control process of the refrigerating apparatus becomes complicated.